RFR: 8361099: Shenandoah: Improve heap lock contention by using CAS for memory allocation [v14]

[Xiaolong Peng]

On Wed, 3 Dec 2025 01:06:29 GMT, Xiaolong Peng <xpeng at openjdk.org> wrote:

>> I suppose we could use conservative values for a first implementation, as long as we file a "low priority" ticket to come back and revisit for improved efficiency at a later time.
>
> We don't really know what need to be recompute until the allocation finishes, we can make it less  conservative, but then we needs more code branches here because the template methods require explicit template parameters.
> 
> I'll create to ticket to follow up on this, given that I also want to see if we can defer the recomputation to the read side, if we can do that we don't even need the ShenandoahHeapAccountingUpdater here.

I have created a bug for the improvement of accounting update: https://bugs.openjdk.org/browse/JDK-8373371

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PR Review Comment: https://git.openjdk.org/jdk/pull/26171#discussion_r2604001291